JP2018120410A - Image forming system, image formation control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable acquiring proofing data of each image forming device in a serial tandem connection without implementing complicated processing.SOLUTION: Disclosed is an image forming system in which a plurality of image forming devices are connected in a serial tandem arrangement, and which implements image data processing to be used for forming images at an image forming unit and comprises a control unit for controlling the image forming devices. The control unit includes a function which causes the image forming device to output an inspection image that attains proofing data of the image forming device and then causes an image reading unit to enable acquiring the reading result. In this function, data for the inspection image that is output by one image forming device is prepared and the data is duplicated, then the originated inspection image data and one of the duplicated inspection image data are sent to the respective image forming devices, and thus control for respectively forming images onto different transfer media is performed at the respective image forming devices based on the inspection image data received by the respective image forming devices.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image forming system in which a plurality of image forming apparatuses are connected in series tandem, an image forming control method, and a program.

In the field of image forming apparatuses that form images on paper, a system in which a plurality of image forming apparatuses are connected in series tandem is known. In such a system, for example, when an image is formed on both sides of a sheet, one side is printed by the upstream image forming apparatus, and an image is formed on the other side of the sheet by the downstream image forming apparatus. Therefore, the productivity of double-sided printing is improved.
However, when a plurality of image forming apparatuses are connected in series tandem, each image forming apparatus prints a separate image, so that a color difference due to a mechanical difference occurs. Therefore, it is necessary to acquire calibration data in order to eliminate the difference in output quality between the image forming apparatuses and to make the image quality uniform among the image forming apparatuses. For this reason, it is possible to obtain calibration data based on the result of printing an inspection image on a sheet by each image forming apparatus and reading the inspection image.

As a method for adjusting a serial tandem system, for example, in Patent Document 1, nonvolatile data that is held in each image forming apparatus and defines control conditions relating to the operation of each image forming apparatus is read by a control apparatus connected to the system. In addition, it is described that it can be rewritten.
Japanese Patent Application Laid-Open No. 2004-26883 discloses a technique for changing a process condition a plurality of times within an adjustable range in conjunction with each image forming apparatus and outputting a test chart every time the process condition is changed a plurality of times. .
In Patent Document 3, when the inspection mode is entered, the inspection chart is printed by the print engine 201 of the printing unit 200, and the same sheet is sent to the printing engine 301 of the printing unit 300, and the inspection chart is not printed. An inspection chart is printed in the area of the surface. Here, the inspection charts of the printing units 200 and 300 have a pattern that does not overlap with each other. Accordingly, the paper discharge unit 400 is a print in which the inspection charts of both the two printing units 200 and 300 are printed on the same surface. The result is obtained, and it is determined that the color reproducibility between the print engines 201 and 301 can be determined by visual confirmation or reading by the reading unit 451.

JP 2004-336335 A JP-A-2015-161924 JP 2007-137010 A

However, Patent Document 1 does not describe a calibration method using an inspection image. In Patent Document 2, test charts to be printed by the respective image forming apparatuses are individually set and printed, which increases the processing load.
Furthermore, in the technique described in Patent Document 3, in order to print the inspection chart of two printing units on one page, it is necessary to create image data for printing by two units at the time of chart creation. A chart image must be generated with the upper half as data for printing by the main machine and the lower half as data for printing by the sub machine. Therefore, there is a problem that a dedicated algorithm for the system connected in series tandem is required to generate the chart image. Further, since different charts are printed on one page, it is impossible to grasp the state of the image at the paper position, the balance, and the like.

  The present invention has been made against the background of the above problems. In a system in which a plurality of image forming apparatuses are connected in series tandem, an image forming system and image forming control capable of obtaining calibration data without performing complicated processing. An object is to provide a method and a program.

That is, among the image forming systems of the present invention, the first aspect of the present invention is an image forming system in which a plurality of image forming apparatuses each having an image forming unit for forming an image on a transfer medium are connected in series tandem,
The image forming unit performs processing of image data used for image formation, and includes a control unit that controls the image forming apparatus,
The control unit has a function of outputting an inspection image for obtaining calibration data of the image forming apparatus by the image forming apparatus and enabling acquisition of a reading result by the image reading unit,
The function prepares inspection image data to be output by one image forming apparatus, duplicates the data, and sends the original inspection image data and one of the copied inspection image data to each image forming apparatus. Each image forming apparatus performs control to form an image on a different transfer medium based on inspection image data received by each image forming apparatus.

In another form of the invention of the image forming system of another form, the image forming apparatus has an image forming control part for controlling the image forming part,
The control unit includes a system control unit that processes image data used in each image forming apparatus and controls each image forming apparatus, and each image formation control unit.

In another form of the invention of the image forming system according to another aspect, in the image forming apparatus serving as the main machine among the plurality of image forming apparatuses, the image forming control unit provided in the image forming apparatus acquires the inspection image data. The inspection image is output to the transfer medium, and the inspection image data is duplicated and sent to the image forming apparatus as a sub machine.
In the image forming apparatus serving as the sub machine, the image forming control unit provided in the image forming apparatus performs transfer different from the transfer medium used for outputting the inspection image in the other image forming apparatus based on the copied inspection image data. An inspection image is output to a medium.

  In another form of the invention of the image forming system according to another aspect, the control unit obtains and analyzes a reading result of the inspection image output from each image forming apparatus, and performs the analysis based on the analysis result. The image forming apparatus to which is output is calibrated.

  In another form of the invention of the image forming system according to another aspect, the control unit obtains and analyzes the reading result of the inspection image output from each image forming apparatus, and based on the analysis result, the image forming apparatus The calibration data is obtained.

  In another form of the invention of the image forming system according to another aspect, the reading result is acquired by the image forming control unit of the image forming apparatus to which the inspection image giving the reading result is output. The image data used in the image forming apparatus is processed and sent to a system control unit that controls each image forming apparatus, and the system control unit creates calibration data used for calibration based on the result.

  In another form of the invention of the image forming system according to another aspect, the image forming control unit of each of the image forming apparatuses performs analysis based on the reading result and sends the analysis result to the system control unit. And

  According to another aspect of the invention of the image forming system, in another aspect, the calibration processing of each image forming apparatus is performed by an image forming control unit included in each image forming apparatus or by a system control unit. .

  In another aspect of the invention of the image forming system according to another aspect, the control unit adjusts the calibration data in at least one image forming apparatus so that the calibration result of each image forming apparatus is within a predetermined range. It is characterized by that.

  According to another aspect of the invention of the image forming system, in another aspect, the control unit stores calibration data used for calibration of each image forming apparatus.

  In another aspect of the invention of the image forming system of the present invention, the control unit stores common calibration data used for calibration of each image forming apparatus.

  In another form of the invention of the image forming system according to another aspect, in the case where the inspection unit prints the inspection image with the preceding image forming apparatus, the control unit transfers the transfer medium on which the inspection image is formed with the preceding image forming apparatus. It is characterized in that control is performed so that the image is fed to the subsequent image forming apparatus without being turned upside down and discharged without image formation by the latter image forming apparatus.

  In another aspect of the invention of the image forming system according to another aspect, in the case where the control unit prints the inspection image with the subsequent image forming apparatus, the transfer unit supplies the transfer medium supplied with the preceding image forming apparatus to the image in the previous stage. The sheet is discharged without image formation by the forming apparatus and sent to the image forming apparatus on the subsequent stage, and the inspection image is printed by one image forming apparatus on the subsequent stage, and the output surface is on the same side as the output surface of the image forming apparatus on the preceding stage. Control is performed so that the paper is discharged so that is positioned.

  In another form of the invention of the image forming system according to another aspect, the image forming system further includes an image reading unit that reads an image of a transfer medium conveyed from the upper side apparatus at a position lower than the plurality of image forming apparatuses. The image reading unit transmits a reading result to the control unit.

  According to another aspect of the invention of the image forming system, in another aspect, the plurality of inspection images output by the plurality of image forming apparatuses are read by the same image reading unit.

Among the image forming control methods of the present invention, the first mode is an image for controlling image formation in an image forming system in which a plurality of image forming apparatuses each having an image forming unit for forming an image on a transfer medium are connected in series tandem. A formation control method comprising:
The image forming apparatus has a function of outputting an inspection image for obtaining calibration data of the image forming apparatus and enabling acquisition of a reading result by the image reading unit,
The function prepares inspection image data to be output by one image forming apparatus, duplicates the data, and sends the original inspection image data and one of the copied inspection image data to each image forming apparatus. Each image forming apparatus performs control to form an image on a different transfer medium based on inspection image data received by each image forming apparatus.

Of the programs of the present invention, the first form is a program executed by a control unit that controls an image forming system in which a plurality of image forming apparatuses each having an image forming unit that forms an image on a transfer medium are connected in series tandem. Because
A step of outputting an inspection image for obtaining calibration data of the image forming apparatus by the image forming apparatus and enabling acquisition of a reading result by the image reading unit;
In the step, inspection image data to be output by one image forming apparatus is prepared, the data is duplicated, and the original inspection image data and one of the duplicated inspection image data are sent to each image forming apparatus. Each image forming apparatus performs control to form an image on a different transfer medium based on inspection image data received by each image forming apparatus.

  According to the present invention, in a system in which a plurality of image forming apparatuses are connected in series tandem, it is possible to appropriately obtain calibration data without performing complicated processing.

1 is a diagram illustrating an outline of a mechanical configuration of an image forming system according to an embodiment of the present invention. Similarly, it is a figure which shows a control block. Similarly, it is a diagram showing a schematic block of the image forming system and a data flow when the chart image data received by the main machine is duplicated and the duplicated chart image data is transmitted to the sub machine. Similarly, it is a flowchart showing a procedure of copying chart image data in the main machine and transmitting the copied chart image data to the sub machine. Similarly, it is a flowchart showing a procedure when a chart image is printed in the main machine. Similarly, it is a flowchart showing a procedure when a chart image is printed in the sub machine. Similarly, when the system controller has calibration data in consideration of the difference between the main machine and the sub machine, it is a diagram showing the relationship between the data. Similarly, it is a flowchart showing a procedure in which the system controller creates calibration data for the main machine and the sub machine. Similarly, when the system controller has calibration data for one unit, it is a diagram showing the relationship between the data. Similarly, it is a flowchart showing a procedure when the system controller creates calibration data for one unit.

Hereinafter, an image forming system according to an embodiment of the present invention will be described.
FIG. 1 is a diagram showing a mechanical outline of the image forming system 1.
The image forming system 1 includes a first image forming apparatus 100, a first reversing apparatus 200, a second image forming apparatus 300, a second reversing apparatus 360, and an image reading apparatus 400 in order from the upstream side in the sheet conveyance direction. And a post-processing device 500. Paper conveyance and communication are possible between the apparatuses.
The image forming system 1 has a configuration in which a first image forming apparatus 100 and a second image forming apparatus 300 are connected in series tandem.

  In addition, the image forming system 1 includes a first image forming apparatus 100, a first reversing apparatus 200, a second image forming apparatus 300, a second reversing apparatus 360, an image reading apparatus 400, and a post-processing apparatus 500. Although the configuration of the image forming system of the present invention is not limited to this, the first image forming apparatus 100 and the second image forming apparatus 300 may configure the image forming system. Further, the number and types of apparatuses in the image forming system of the present invention are not limited to the above, and may include other apparatuses. For example, a plurality of paper feed trays may be provided in the front stage of the first image forming apparatus 100. A sheet feeding device having the above may be provided. Furthermore, in the image forming system of the present invention, the number of image forming apparatuses connected in series may be three or more.

In the image forming system 1, the first image forming apparatus performs printing on the first surface of the sheet, the first reversing apparatus 200 reverses the sheet, and the second image forming apparatus 300 reverses the first surface of the sheet. By performing printing on a certain second surface, it is possible to perform double-sided printing.
In this embodiment, the first image forming apparatus 100 is appropriately referred to as a main machine and the second image forming apparatus 300 is appropriately referred to as a sub machine. However, the main machine and the sub machine can be reversed in terms of control.

First, the first image forming apparatus 100 will be described.
The first image forming apparatus 100 has an operation display unit 123 at the top of the housing. The operation display unit 123 is configured by a display unit and an operation unit including an LCD, and information display and operation input are possible. Note that the operation display unit 123 may be one in which the operation unit and the display unit are integrated, such as an LCD having a touch panel.

  The first image forming apparatus 100 includes a document feeding unit 130 at the top of the housing. The document feeder 130 can automatically feed a document and read an image of the document with a scanner (not shown). Note that reading of a document can also be performed on a platen glass (not shown).

  A paper feed tray 101 is provided inside the housing of the first image forming apparatus 100. Paper is stored in the paper feed tray 101. The paper corresponds to the transfer medium of the present invention. In the present invention, the material of the transfer medium is not limited to paper, and a transfer medium of a desired material such as cloth or plastic can be used.

  A conveyance path 102 is connected to the paper feed tray 101. The transport path 102 transports paper supplied from the paper feed tray 101 and paper supplied from outside the housing. The downstream side of the conveyance path 102 is connected to the conveyance path 202 of the first reverse device 200 at the subsequent stage.

  A leading edge detection unit 103 is provided in the middle of the conveyance path 102. The leading edge detection unit 103 can be configured by an optical sensor, and can detect the edge of the conveyed paper by ON / OFF of light detection. The timing of image formation can be determined based on the detection result by the tip detection unit 103.

Further, an image forming unit 124 is provided in the middle of the conveyance path 102 at a position downstream of the leading edge detection unit 103. The image forming unit 124 forms an image on a sheet conveyed through the conveyance path 102.
In the image forming unit 124, a photosensitive member 104 for each color, a secondary transfer unit 107, and a reading unit 106 are arranged around the intermediate transfer belt 105 in the order of the belt rotation direction. The secondary transfer unit 107 is provided at a position sandwiching the conveyance path 102 with respect to the intermediate transfer belt 105. A fixing unit 108 is disposed in the middle of the conveyance path 102 and at a position downstream of the secondary transfer unit 107. Further, around the photosensitive member 104, a charger, an LD, a developing unit, and the like (not shown) are provided.
Although the first image forming apparatus 100 has a configuration for performing color printing, the present invention may be an apparatus for performing monochrome printing.

Next, the first reversing device 200 will be described.
The first reversing device 200 has a conveyance path 202. The upstream side of the conveyance path 202 is connected to the conveyance path 102 of the first image forming apparatus 100, and the downstream side is connected to the conveyance path 302 of the second image forming apparatus 300 at the subsequent stage.
In the conveyance path 202, the reverse conveyance path 202a is branched in the middle, and the downstream side of the reverse conveyance path 202a joins the conveyance path 202 upstream of the branch point. The reversing conveyance path 202a has a reversing portion 202b that can be conveyed with the front and rear being switched.
In the first reversing device 200, the paper can be reversed. When the paper is reversed, the paper is transported from the transport path 202 to the reverse transport path 202a, and the reversing unit 202b of the reverse transport path 202a is used to transport the paper. The front and back sides of the sheet are reversed by switching the front and rear sides and transporting them downstream of the reversal transport path 202a. The reversed paper is circulated to the conveyance path 202 and can be conveyed downstream of the conveyance path 202. If the paper is not reversed, the paper is conveyed on the conveyance path 202 as it is without being sent to the reverse conveyance path 202a.

Next, the second image forming apparatus 300 will be described.
The second image forming apparatus 300 is provided with a conveyance path 302, the upstream side of the conveyance path 302 is connected to the conveyance path 202 of the first inversion device 200 at the front stage, and the downstream side of the conveyance path 302 is at the rear stage. It is connected to the conveyance path 362 of the second reversing device 360. The conveyance path 302 conveys the sheet conveyed from the first reversing device 200.

  A tip detection unit 303 is provided in the vicinity of the conveyance path 302. The leading edge detection unit 303 can be configured by an optical sensor, and can detect the leading edge of the conveyed paper by ON / OFF of light detection. The image formation timing can be determined based on the detection result of the leading edge detection unit 303.

In the vicinity of the conveyance path 302, an image forming unit 324 is provided at a position downstream of the leading edge detection unit 303. The image forming unit 324 can form an image on a sheet conveyed through the conveyance path 302.
In the image forming unit 324, a photoconductor 304 for each color, a secondary transfer unit 307, and a reading unit 306 are arranged around the intermediate transfer belt 305 in the order of the belt rotation direction. Further, a fixing unit 308 is disposed in the middle of the conveyance path 302 at a position downstream of the secondary transfer unit 307. In addition, a charger, an LD, a developing unit, and the like (not shown) are provided around the photosensitive member 304.
Note that the second image forming apparatus 300 has a configuration for performing color printing, but may be an apparatus for performing monochrome printing.

Next, the second reversing device 360 will be described.
The second reversing device 360 has a conveyance path 362, the upstream side of the conveyance path 362 is connected to the conveyance path 302 of the second image forming apparatus 300, and the downstream side of the conveyance path 362 is the downstream image. It is connected to the conveyance path 402 of the reading device 400. A reverse conveyance path 362a is branched in the middle of the conveyance path 362, and the downstream side of the reverse conveyance path 362a joins the conveyance path 362 upstream of the branch point. The reversing conveyance path 362a has a reversing unit 362b that can convey the reversing front and rear.

  In the second reversing device 360, the paper can be reversed. When the paper is reversed, the paper is transported from the transport path 362 to the reverse transport path 362a, and the reversing unit 362b of the reverse transport path 362a The front and back sides of the paper are reversed by switching the front and rear sides and transporting them downstream of the reverse transport path 362a. The reversed paper is circulated to the conveyance path 362 and can be conveyed downstream of the conveyance path 362. If the paper is not reversed, the paper is conveyed on the conveyance path 362 as it is without being sent to the reverse conveyance path 362a.

Next, the image reading apparatus 400 will be described. The image reading device 400 is arranged at the rear stage of the second reversing device 360, that is, at the lower side of the first image forming apparatus 100 and the second image forming apparatus 300.
The image reading apparatus 400 has a conveyance path 402, the upstream side of the conveyance path 402 is connected to the conveyance path 362 of the second reversing device 360, and the downstream side of the conveyance path 402 is the conveyance path 502 of the post-processing device 500. It is connected to the.

An image reading unit 410 is disposed in the conveyance path 402. The image reading unit 410 can be configured by a CMOS sensor, a CCD sensor, or the like, and can read an image on the upper surface of the paper. The image reading unit may be a line sensor or a colorimeter that reads an image at a point. When a colorimeter is used, adjustment charts such as patches formed on paper are read by the colorimeter, the results are sent to other devices, and analysis is performed to adjust each image forming device. It can be carried out. Note that a configuration in which the reading result is analyzed in the image reading apparatus 400 may be employed.
In this embodiment, the image reading apparatus is described as having one image reading unit. However, the image reading apparatus may have a plurality of image reading units. In that case, the adjustment data output from the plurality of image forming apparatuses is read using one image reading unit.

Next, the post-processing device 500 will be described.
The post-processing apparatus 500 has a conveyance path 502, and the upstream side of the conveyance path 502 is connected to the conveyance path 402 of the image reading apparatus 400.
A post-processing unit 501 is provided in the middle of the conveyance path 502, and the post-processing unit can perform appropriate processing such as stapling, punching, and booklet processing on sheets on the conveyance path. Processing may be performed. Alternatively, the post-processing apparatus 500 may discharge the paper without performing post-processing.

  When an image is formed on a sheet by the first image forming apparatus, a latent image is formed by the LD on the photosensitive member 104 charged based on the image data, and a developing unit develops the latent image to create a toner image. The toner image on the photoreceptor 104 is transferred to the intermediate transfer belt 105, and the image on the intermediate transfer belt 105 is transferred to a sheet conveyed through the conveyance path 102 by the secondary transfer unit 107. The paper is conveyed from the paper feed tray 101 or the like. Thereafter, the fixing unit 108 applies heat and pressure to the sheet conveyed by the conveying path 102 to fix the image on the sheet. The sheet on which the image is fixed is conveyed to the outside of the first image forming apparatus as it is face-up without being reversed by the first reversing device 200.

The reading unit 106 disposed around the intermediate transfer belt 105 is located downstream of the secondary transfer unit 107 in the belt rotation direction, and includes adjustment patches formed on the intermediate transfer belt 105. The pattern can be read.
The sheet on which the image is formed is discharged from the first image forming apparatus 100, reversed by the first reversing apparatus 200 as necessary, and conveyed to the second image forming apparatus 300. For example, when printing on a paper surface different from the paper surface on which the image is formed by the first image forming apparatus 100, after the image is formed by the first image forming apparatus 100, the paper is reversed by the first reversing device 200 and the second image is formed. The sheet is conveyed to the forming apparatus 300 and an image is formed on the upper surface of the sheet by the second image forming apparatus 300.

When the second image forming apparatus 300 forms an image on a sheet, a latent image is formed on the photosensitive member 304 charged based on the image data by an LD, and the latent image is developed by a developing device to create a toner image. The toner image is transferred to the intermediate transfer belt 305, and the image on the intermediate transfer belt 305 is transferred to a sheet in the secondary transfer unit 307. The paper is conveyed from the paper feed tray 101 or the like. Thereafter, the fixing unit 308 applies heat and pressure to the paper, thereby fixing the image on the paper. The sheet on which the image is formed is conveyed out of the apparatus with face-up as it is.
Further, in the vicinity of the intermediate transfer belt 305, a reading unit 306 is installed downstream of the secondary transfer unit 307 in the belt rotation direction. The reading unit 306 can read adjustment patches and patterns formed on the intermediate transfer belt 305.

  Note that when the second image forming apparatus 300 does not form an image on the sheet on which the image is formed by the first image forming apparatus 100, the image forming unit 324 does not perform image formation, and the sheet passes through the conveyance path 302 on the downstream side. It is conveyed to. In addition, when image formation is not performed by the first image forming apparatus 100 and image formation is performed only by the second image forming apparatus 300, the first image forming apparatus is used for paper fed by the first image forming apparatus 100. In 100, the sheet is discharged as it is without image formation, and is carried into the second image forming apparatus 300 for image formation.

Next, the electrical configuration of the image forming system 1 will be described.
FIG. 2 is a functional block diagram of the image forming system 1.
The first image forming apparatus 100 includes a printer controller 110, a scanner unit 122, an operation display unit 123, an image forming unit 124, a communication unit 125, and a main control unit 150 as main components.

  The printer controller 110 includes a controller control unit 111, a LAN-IF unit 112, an image memory (DRAM) 113, an HDD 114, and a DRAM control unit 115. The controller control unit 111, the LAN-IF unit 112, an image memory ( DRAM) 113 and HDD 114 are each connected to a DRAM control unit 115. The DRAM control unit 115 is connected to the selection unit 153 of the main control unit 150 via the PCI bus.

The controller control unit 111 includes a CPU, a ROM, a RAM, and the like, and controls the printer controller based on a program operated by the CPU.
The LAN-IF unit 112 is connected to the LAN 3 and can communicate with the external device 4 such as a PC connected to the LAN 3. Job data and the like can be received from the external device 4, a job can be executed in the first image forming apparatus based on the received job data, and communication with other devices in the image forming system 1 can be performed. It is possible to output a job in conjunction with other devices. As job data, in addition to image formation, it is also possible to execute adjustment chart image formation and adjustment based on the read result of the formed adjustment chart image.

The external apparatus 4 can transmit an image quality adjustment execution instruction and adjustment chart image data to the first image forming apparatus 100.
Note that when performing image quality adjustment, adjustment chart image data for image quality adjustment may be provided in a storage unit inside the main body, and the adjustment may be performed by reading out based on an instruction from the operator. For example, the adjustment of the image forming system 1 can be performed based on an operation on the operation display unit 123. The adjustment chart image corresponds to the inspection image of the present invention.

  When the first image forming apparatus 100 acquires image data for printing, the image data can be received via the LAN-IF unit 112. The received image data is stored in the image memory (DRAM) 113 or the HDD 114 via the DRAM control unit 115.

The scanner unit 122 includes a line image sensor 122a and a scanner control unit 122b. The line image sensor 122a and the scanner control unit 122b are electrically connected, and the scanner control unit 122b controls the line image sensor 122a to control the sheet fed by the document feeding unit 130 or the sheet on the platen glass. Images can be read optically.
The line image sensor 122 a is connected to the reading processing unit 152 of the main control unit 150, and the scanner control unit 122 b is connected to the CPU 151 of the main control unit 150.

The operation display unit 123 includes a display unit 123a, an operation unit 123b, and an operation control unit 123c. The operation control unit 123c is connected to the display unit 123a and the operation unit 123b.
The display unit 123a can be configured by an LCD, and the operation unit can be configured by a touch panel, an operation button outside the LCD, or the like. The operation control unit 123c includes a CPU, ROM, RAM, a program that operates on the CPU, and the like, and controls the operation display unit 123. The operation display unit 123 can display a setting screen and an operation screen, display a warning, notify a user, accept an operation input, and the like.

  The image forming unit 124 includes an LD 124a, a printer control unit 124b, a charger, a photoreceptor, a developing device, a transfer unit, a fixing unit, and the like (not shown). The printer control unit 124b can control the entire image forming unit 124, and the printer control unit 124b controls each unit according to an instruction from the CPU 151 to form an image. When image formation is performed, the LD 124a forms a latent image on the photoconductor based on the image data, the developing unit develops the latent image to create a toner image, and the transfer unit transfers the toner image onto the paper and fixes it. The device fixes the toner image on the paper by heat or the like. The image forming unit may perform monochrome printing or color printing.

Next, the main control unit 150 will be described. The main control unit 150 controls the first image forming apparatus 100.
The main control unit 150 has a CPU 151. The CPU 151 is connected to the DRAM control units 153a, 153b, the HDD 156, the ROM 159a, the RAM 159b, and the nonvolatile memory 159c. The DRAM control unit 153a is connected to the selection unit 153, the compression / decompression unit 154a, and the image memory 155a, and the DRAM control unit 153b is connected to the selection unit 153, the compression / decompression unit 154b, and the image memory 155b. Has been.
The selection unit 153 is connected to the read processing unit 152 and the write processing unit 158, and is further connected to the DRAM control unit 115 through the PCI bus. The reading processing unit 152 is connected to the line image sensor 122 a of the scanner unit 122, and the writing processing unit 158 is connected to the LD 124 of the image forming unit 124.
The CPU 151 is connected to the scanner control unit 122b, the operation control unit 123c, the printer control unit 124b, and the communication unit 125. The communication unit 125 is connected to the communication unit 325 of the second image forming apparatus 300, the communication unit 405 of the image reading apparatus 400, and the communication unit 505 of the post-processing apparatus.

The CPU 151 controls the entire first image forming apparatus 100 by executing a program and grasps the state of the entire first image forming apparatus 100. The CPU 151 and the program that operates on the CPU 151 serve as the image forming control unit of the present invention.
Further, the program may include a program for processing image data used in the image forming system 1 and controlling each image forming apparatus. In that case, the CPU 151 and the program operating on the CPU 151 function as a system control unit. The system control unit may be located outside the housing of the image forming apparatus and connected to be communicable with the image forming apparatus. In the image forming apparatus, the system control unit is configured separately from the image forming control unit. It may be provided. The image formation control unit and the system control unit are included in the control unit of the present invention.

The program may be stored in the ROM 159a, or may be stored in the HDD 156 or an external storage medium. The storage medium may be removed and distributed.
When the adjustment of the first image forming apparatus 1 is executed, the image formation control unit of the first image forming apparatus duplicates the adjustment chart image data received from the system control unit, and the copied adjustment chart image data is copied. The image can be transmitted to the second image forming apparatus 300 via the communication unit 125. Further, the image forming apparatus can be adjusted based on the result of reading the adjustment chart image.
Note that data duplication may be performed by the system control unit, and the duplicated data may be transmitted to the image forming apparatus.

  The RAM 159b can be used as a work memory when the CPU 151 executes a program. The nonvolatile memory 159c stores user data, system data, paper settings, operation parameters, various setting values, and the like. The nonvolatile memory 159c stores various parameters for creating configuration data based on adjustment data and reading results. The adjustment data can also be acquired from the outside. There may be a plurality of adjustment data.

The read processing unit 152 performs a predetermined process on the data acquired by the scanner unit 122. For example, the analog image signal input from the scanner unit 122 is subjected to various types of processing such as analog signal processing, A / D (Analog to Digital) conversion processing, and shading processing, and digital image data is generated and output to the selection unit 153. .
The selection unit 153 selects either the DRAM control unit 153a or the DRAM control unit 153b based on an instruction from the CPU 151. You can select either the data reading side or the data writing side.
The selection unit 153 is connected to the DRAM control unit 115 of the printer controller 110 through the PCI bus, and data can be transmitted and received between the printer controller 110 and the main control unit 150.

The DRAM control unit 153a controls the writing of data to the image memory 155a and the reading of data from the image memory 155a, and also the control when the compression / decompression unit 154a compresses or decompresses the image data.
The DRAM control unit 153b controls the writing of data to the image memory 155b and the reading of data from the image memory 155b, and also the control when the compression / decompression unit 154b compresses or decompresses the image data.

  The compression / decompression units 154a and 154b can compress the image data and decompress the compressed image data. The compressed or decompressed data is stored in the image memory 155a or the image memory 155b.

The HDD 156 stores print job data (job data), image data, setting data, and the like received from the printer controller 110.
The writing processing unit 158 outputs a signal for controlling the LD 124a of the image forming unit 124 according to the image data read from the image memory 155a and the image memory 155b and expanded.

Next, the electrical configuration of the second image forming apparatus 300 will be described.
The second image forming apparatus 300 includes a printer controller 310, a scanner unit 322, an operation display unit 323, an image forming unit 324, a communication unit 325, and a main control unit 350 as main components.

  The printer controller 310 includes a controller control unit 311, a LAN-IF unit 312, an image memory (DRAM) 313, an HDD 314, and a DRAM control unit 315. These configurations are the same as the configuration of the printer controller 110 in the first image forming apparatus 100, and the same operations are performed, so the details are omitted. Note that the second image forming apparatus 300 may not include the printer controller 310.

The scanner unit 322 includes a line image sensor 322a and a scanner control unit 322b. The line image sensor 322a and the scanner control unit 322b are electrically connected, and the scanner control unit 322b controls the line image sensor 322a. .
The line image sensor 322 a is connected to the reading processing unit 352 of the main control unit 350, and the scanner control unit 322 b is connected to the CPU 351 of the main control unit 350.
Note that the second image forming apparatus 300 may not include the scanner unit 322.

The operation display unit 323 includes a display unit 323a, an operation unit 323b, and an operation control unit 323c. The operation control unit 323c is connected to the display unit 323a and the operation unit 323b. The display unit 323a can be configured by an LCD, and the operation unit can be configured by a touch panel, an operation button outside the LCD, or the like. The operation control unit 323c includes a CPU, ROM, RAM, a program that operates on the CPU, and the like, and controls the operation display unit 323. The operation display unit 323 can display a setting screen and an operation screen, display a warning, notify a user, accept an operation input, and the like.
Note that the second image forming apparatus may not include the operation display unit 323. In that case, setting and display for the second image forming apparatus 300 may be performed via the operation display unit 123 of the first image forming apparatus 100.

  The image forming unit 324 includes an LD 324a, a printer control unit 324b, a charger, a photoreceptor, a developing device, a transfer unit, a fixing unit, and the like (not shown). The printer control unit 324b controls the entire image forming unit 324. In response to an instruction from the CPU 351, the printer control unit 324b controls each unit to form an image. The operation of the image forming unit 324 is the same as that of the image forming unit 124 of the first image forming apparatus 100.

The main control unit 350 controls the second image forming apparatus 300.
The main control unit 350 has a CPU 351. The CPU 351 is connected to the DRAM control unit 353a, 353b, the HDD 356, the ROM 359a, the RAM 359b, and the nonvolatile memory 359c. The DRAM control unit 353a is connected to the selection unit 353, the compression / decompression unit 354a, and the image memory 355a, and the DRAM control unit 353b is connected to the selection unit 353, the compression / decompression unit 354b, and the image memory 355b. Has been.
The selection unit 353 is connected to the read processing unit 352 and the write processing unit 358, and is further connected to the DRAM control unit 115 through the PCI bus. The reading processing unit 352 is connected to the line image sensor 322 a of the scanner unit 322, and the writing processing unit 358 is connected to the LD 324 of the image forming unit 324.
The CPU 351 is connected to the scanner control unit 322b, the operation control unit 323c, the printer control unit 324b, and the communication unit 325. The communication unit 325 is connected to the communication unit 125 of the first image forming apparatus 100, the communication unit 405 of the image reading device 400, and the communication unit 505 of the post-processing device.

  The CPU 351 controls the entire second image forming apparatus 300 by executing a program and grasps the state of the entire second image forming apparatus 300. The CPU 351 and the program operating on the CPU 351 can serve as an image formation control unit that controls the second image forming apparatus. The program may be stored in the ROM 359a, or may be stored in the HDD 356 or an external storage medium. The storage medium may be removed and distributed. The image forming control unit of the second image forming apparatus is included in the control unit of the present invention together with the image forming control unit and the system control unit of the first image forming apparatus 100 described above.

  When image quality adjustment of the second image forming apparatus is performed, the image formation control unit forms an adjustment chart image on a sheet based on the received data of the adjustment chart image, and reads a reading result obtained by reading the adjustment chart image. Analyze and adjust image quality. When adjustment is performed, a reading result obtained by reading an adjustment chart image formed by another image forming apparatus is acquired, and the adjustment is performed so that the difference from the other image forming apparatus disappears or falls within a predetermined range. It is possible. The predetermined range is determined in advance as an allowable range.

  The RAM 359b can be used as a work memory when the CPU 351 executes a program. The nonvolatile memory 359c stores user data, system data, paper settings, operation parameters, various setting values, and the like. The non-volatile memory 359c stores various parameters necessary for adjusting the image forming unit.

  The read processing unit 352 performs predetermined processing on the data acquired by the scanner unit 322. For example, the analog image signal input from the scanner unit 322 is subjected to various types of processing such as analog signal processing, A / D (Analog to Digital) conversion processing, and shading processing, and digital image data is generated and output to the selection unit 353. .

The selection unit 353 selects either the DRAM control unit 353a or the DRAM control unit 353b based on an instruction from the CPU 351. You can select either the data reading side or the data writing side.
The selection unit 353 is connected to the DRAM control unit 315 of the printer controller 310 through the PCI bus, and data can be transmitted and received between the printer controller 310 and the main control unit 350.

The DRAM control unit 353a controls the writing of data to the image memory 355a and the reading of data from the image memory 355a, and also the control when the image data is compressed or decompressed by the compression / decompression unit 354a.
The DRAM control unit 353b controls the writing of data to the image memory 355b and the reading of data from the image memory 355b, and the control when the image data is compressed or expanded by the compression / decompression unit 354b.

  The compression / decompression units 354a and 354b can compress the image data and decompress the compressed image data. The compressed or decompressed data is stored in the image memory 355a or the image memory 355b.

The HDD 356 stores print job data (job data), image data, setting data, and the like received from the printer controller 310. The HDD 356 and the nonvolatile memory 359c can be used as a storage unit of the present invention.
The writing processing unit 358 outputs a signal for controlling the LD 324a of the image forming unit 324 in accordance with the image data read from the image memory 355a and the image memory 355b and expanded.

Next, the electrical configuration of the image reading apparatus 400 will be described.
The image reading apparatus 400 includes a reading control unit 401, a communication unit 405, and an image reading unit 410. The reading control unit 401 is connected to the communication unit 405 and the image reading unit 410. The communication unit 410 includes the communication unit 125 of the first image forming apparatus 100, the communication unit 325 of the second image forming apparatus 300, and the post-processing apparatus. Each is connected to a communication unit 505. The reading control unit 401 includes a CPU, a ROM, a RAM, and the like, and can control each unit of the image reading apparatus 400 by a program operated by the CPU.

The image reading unit 410 includes a reading unit, a conveyance unit, and the like, and can read an image on a sheet under the control of the reading control unit 401. The image reading unit 410 can continuously read images of the conveyed paper. In addition, the reading control unit 401 can receive external control via the communication unit 405, and the acquired read image can be obtained via the communication unit 405 by using the image forming control unit of the first image forming apparatus 100. Or an image formation control unit, a system control unit, or the like of the second image forming apparatus 300. It is also possible to transmit to an information processing apparatus connected to the image forming apparatus 1.
In the first image forming apparatus 100 and the second image forming apparatus 300, calibration data such as image density balance and color tone can be obtained using the reading result acquired by the image reading apparatus 400.

Next, the electrical configuration of the post-processing apparatus 500 will be described.
The post-processing apparatus 500 includes a post-processing control unit 501, a communication unit 505, and a post-processing unit 510. The post-processing control unit 501 is connected to the communication unit 505 and the post-processing unit 510. The communication unit 510 includes the communication unit 125 of the first image forming apparatus 100, the communication unit 325 of the second image forming apparatus 300, and the image. It is connected to the communication unit 405 of the reading device 400. The post-processing control unit 401 is configured by a CPU, a ROM, a RAM, and the like, and controls each unit of the post-processing device 500 by a program operated by the CPU. The post-processing unit 510 can perform predetermined post-processing on the conveyed paper. The post-processing control unit 501 can transmit and receive data via the communication unit 505.

(Embodiment 1)
Next, an operation for adjusting the image quality of the output image in the image forming system 1 will be described.
The first image forming apparatus 100 will be described as a main machine, and the second image forming apparatus 300 will be described as a sub machine. In the present invention, either the first image forming apparatus 100 or the second image forming apparatus 300 may be handled as the main machine, but is connected to the system controller in a controllable manner and communicates with other image forming apparatuses. Possible devices can be the main machine. The system controller corresponds to the system control unit of the present invention, and performs processing of image data used in the image forming apparatus and control of each image forming apparatus. The system controller may be provided in the image forming apparatus and may be provided in the same unit together with the image forming control unit, or may be provided in a unit different from the image forming control unit. Further, it may be provided outside the image forming apparatus.

  In the case of the serial tandem image forming system, the front and back images are printed separately by the main machine and the sub machine, resulting in a difference in color due to a machine difference. Therefore, a system controller that controls the image forming apparatus has calibration data for performing calibration in accordance with the image forming apparatus. The calibration data corresponds to the calibration data of the present invention. If calibration data is held, calibration data can be used to calibrate so that each image forming apparatus can obtain the same image quality during normal image formation, and can easily return to the state before calibration. be able to.

  In the present embodiment, the controller prepares the adjustment chart image data for calibration in the same manner as when there is one image forming apparatus, and transmits it to the first image forming apparatus 100 on the upstream side (main machine). The first image forming apparatus 100 duplicates the adjustment chart image data and transmits the copied adjustment chart image data to the second image forming apparatus so that the adjustment chart image is obtained.

In FIG. 3, the controller prepares the chart image for adjustment and transmits it to the first image forming apparatus 100 (main machine), and the first image forming apparatus 100 (main machine) transmits the duplicated data to the sub machine. To do.
When adjusting the output in the image forming system 1, as shown in FIG. 3, the system controller transmits the page data D1 for one page having the chart C to the main machine, as in the case of adjusting the single machine. To do. The main machine duplicates the received data, generates page data D2 of the second page having the chart C, and transmits the data to the sub machine.

The above operation will be described with reference to the flowchart of FIG.
FIG. 4 is a flowchart showing a procedure for copying chart image data in the main image forming apparatus and transmitting it to the sub-device.
When the operation is started (step S100), the chart image is transferred from the controller to the main machine of the image forming apparatus (step S101). The image forming apparatus (main machine) duplicates the page data of the chart image received from the controller (step S102), transfers the duplicated chart image data to the sub machine (step S103), and ends the procedure.

Thereafter, each image forming apparatus forms a chart image on the sheet based on the received chart image data.
In the first image forming apparatus, when the chart is printed as the first page, the first page is printed by the main machine, and the sheet is conveyed to the sub machine with the face up without performing the paper inversion. The sub machine discharges the sheet as it is without printing (the face is kept up). Thereafter, the color of the paper discharged from the sub-machine is measured by the image reading device, the reading result is transmitted to the first image forming device, and the first image forming device analyzes the reading result.

FIG. 5 is a flowchart showing a procedure for printing a chart image in the first image forming apparatus as the main machine.
When the operation is started (step s200), it is determined whether or not the image reading apparatus is to be read (step S201). When reading is performed (step S201, Yes), the process proceeds to step S202. When reading is not performed (step S201, No), the process proceeds to step S208.

  When reading, that is, when printing a chart image, the main machine prints the chart image of the first page (step S202). Thereafter, the sheet is not reversed by the first reversing device 200 connected to the subsequent stage of the main machine (step S203), and the sheet is conveyed to the subsequent sub-machine in the face-up state. The sub-machine does not perform printing, and the received paper is discharged to the subsequent stage with the face up (step S204). Paper reversal is not performed in the second reversing device 360 connected to the rear stage of the sub machine (step S205), and the paper is conveyed to the rear stage of the paper while keeping Face up. Thereafter, the chart image on the upper surface of the sheet is measured by the image reading apparatus (step S206), and the image forming apparatus that has printed the chart image analyzes the measured color data (step S207), and the procedure is terminated.

  When the image reading device is not read (step S201, No), the main machine prints an image on the back surface (second page) (step S208), and the first reversing device 200 connected to the subsequent stage of the main machine. Then, the paper is reversed (step S209). The sheet is conveyed to the subsequent stage in the face down state. After that, the front side (first page) is printed by the sub machine (step S210), the paper reversing device connected to the rear stage of the sub machine is not reversed (step S211), and the face down is set to the rear stage. The sheet is conveyed and discharged to the post-processing apparatus (step S212), and the procedure is terminated.

  Further, when reading is performed by the image reading apparatus and the chart is printed on the sub machine as the second page, the main machine does nothing and transports the paper to the sub machine. The sub-printer prints the second page and discharges the paper as face up without turning over the paper. The paper taken out from the sub-machine is color-measured by the image reader and the result is analyzed.

The above operation will be described with reference to the flowchart of FIG.
FIG. 6 is a flowchart showing a procedure for printing a chart image in the first image forming apparatus which is a sub machine.
When the operation is started based on the job, it is determined whether the image reading apparatus performs reading (step S301). If it is a job to be read (step S301, Yes), the process proceeds to step S302, and the main machine does nothing and discharges to the subsequent stage. When reading is not performed (step S301, No), the process proceeds to step S308.

  After step S302, the first reversing device 200 connected to the rear stage of the main machine does not perform the paper reversal (step S303), and the sheet is conveyed to the subsequent sub-machine in the face-up state. The sub machine prints the chart image of the second page duplicated by the main machine (step S304), and discharges the paper to the subsequent stage while keeping the face up. The second reversing device 360 connected to the rear stage of the sub machine does not perform the paper reversal (step S305), and transports the paper to the rear stage with the face up. Thereafter, the chart image on the upper surface of the sheet is measured by the image reading apparatus (step S306), and the measured data is read to the image forming apparatus on which the chart image is printed. The image forming apparatus that has received the reading result analyzes the colorimetric data (step S307) and ends the procedure.

  When reading is not performed by the image reading apparatus (No in step S301), the main machine prints an image on the back side (second page) (step S308), and a sheet reversing apparatus (first page) connected to the rear stage of the main machine. The sheet is reversed by the 1 reversing device 200) (step S309). The sheet is conveyed to the subsequent stage in the face down state. Thereafter, the front side (first page) is printed by the sub machine (step S310), and the paper reversing device (second reversing device 360) connected to the subsequent stage of the sub machine is not executed (step S311). , Face down, transported to the subsequent stage, discharged to the post-processing apparatus (step S312), and the procedure ends.

In the image forming system 1, when adjusting each image forming apparatus in the system, the output of each image forming apparatus is adjusted based on the reading result obtained by reading the adjustment chart image, and the output from each image forming apparatus is adjusted. Ensure that the results are the same.
At this time, if the controller can hold a plurality of calibration data in consideration of the case of the main / sub machine, the image forming apparatus displays both of the reading results of the chart images printed by the main machine / sub machine. The controller is notified, and the controller creates calibration data for the main machine and the sub machine. In this case, the controller creates calibration data so that there is no difference between the image forming apparatuses. Thereby, it is possible to make the output results of the respective image forming apparatuses the same.

FIG. 7 shows the relationship between the reading result, analysis result, and calibration data held by the controller when the controller has calibration data that takes into account the difference between the main machine and the sub machine.
In this case, the chart image printed by the main machine is transmitted to the image forming apparatus (first image forming apparatus 100) of the main machine and the reading result acquired by the image reading apparatus is analyzed by the first image forming apparatus 100. The analysis result is transmitted to the system controller. Similarly, the chart image printed by the sub machine is transmitted to the image forming apparatus (second image forming apparatus 300) of the main machine, and the second image forming apparatus 300 analyzes the reading result acquired by the image reading apparatus. The analysis result is transmitted to the system controller. After that, the system controller creates calibration data for the main machine and the sub machine based on the analysis result. The calibration data is calculated by the system controller so that the output results of the main machine and the sub machine are the same. In this figure, each image forming apparatus analyzes the reading result, but the analysis may be performed by a controller.

The above operation will be described with reference to the flowchart of FIG.
FIG. 8 shows the procedure for notifying the system controller of both the data printed and measured by the main machine and the sub machine, and the system controller using the data to create calibration data for the main machine and the sub machine. It is a flowchart to show.
When the operation is started, first, a chart image is printed on the main machine in order to create calibration data for the main machine (step S401). Then, the paper printed by the main machine is transported to the image reading apparatus in the face-up state, and the image reading apparatus reads the image on the paper (step S402). The image reading apparatus transfers the read image to the main machine (step S403), the main machine analyzes the read image (step S404), and passes the analysis result to the controller (step S405). The system controller creates calibration data for the main machine using the received analysis result (step S406). Here, creation of calibration data for the main machine is completed.
Next, calibration data for the sub machine is created. First, a chart image is printed by the sub machine (step S407). Then, the paper printed by the sub-machine is conveyed to the image reading device in the face-up state, and the image reading device reads the image on the paper (step S408). The image reading device transfers the read image to the sub machine (step S409), the sub machine analyzes the read image (step S410), and passes the analysis result to the controller (step S411).
The controller creates calibration data for the sub machine using the received analysis result (step S412), and the creation of the calibration data for the sub machine is completed. When step S412 is completed, the procedure ends.

(Embodiment 2)
In the above operation, a case has been described in which the controller can hold a plurality of calibration data in consideration of the main and sub machines, but the controller does not take into account the difference between the main and sub machines. If you have calibration data (use the same calibration data for both the front and back surfaces), the image forming device refers to the data printed and measured by the main and sub machines, and outputs them on the main and sub machines. Adjustment is performed on the image forming apparatus side so that the results are the same. The controller sends to the controller the calorimetric data in which there is no difference between the main machine and the sub machine, and the controller creates one calibration data using the data.

FIG. 9 shows the relationship between the reading result, analysis result, and calibration data held by the controller when the controller has calibration data for one unit.
In this case, the reading results of the main machine and the sub machine acquired by the image reading apparatus are transmitted to the main machine and the sub machine, respectively. Thereafter, adjustment is performed on the image forming apparatus side so that the output results of the main machine and the sub machine are the same, and the result is transmitted to the controller. The adjustment may be performed by one image forming apparatus or both image forming apparatuses. In this embodiment, it is desirable to perform calibration adjustment with the sub machine so as to match the main machine. The controller creates calibration data based on the received analysis result.

The above operation will be described with reference to the flowchart of FIG.
FIG. 10 is a flowchart showing a procedure in which the controller creates calibration data for one unit.
When the operation is started, a chart image is printed by the main machine (step S501). Then, the paper printed by the main machine is transported to the image reading apparatus in the face-up state, and the image reading apparatus reads the image on the paper (step S502). The image reading apparatus transfers the read image to the main machine (step S503), and the main machine analyzes the read image (step S504).

Next, the chart image is printed by the sub machine (step S505). Then, the paper printed by the sub-machine is transported to the image reading apparatus while Face up, and the image reading apparatus reads the image on the paper (step S506). The image reading apparatus transfers the read image to the sub machine (step S507), and the sub machine analyzes the read image (step S508).
Thereafter, the sub machine receives the analysis result performed by the main machine (step S509), and the sub machine performs adjustment so that the output result is the same as that of the main machine (step S510).
The main machine passes the analysis result to the controller (step S511), and the controller creates calibration data common to the main machine and the sub machine using the received analysis result (step S512). Thereafter, the procedure is terminated.

  According to the present embodiment, the calibration of the controller for the main machine and the sub machine can be executed in the same manner as the single machine for the controller using only one reading device (ICCU) at the time of serial tandem. That is, the system controller does not need to prepare a chart image for serial tandem, and can use the same chart image / calibration algorithm as that of a single machine.

  As mentioned above, although this invention was demonstrated based on the said embodiment, the range of this invention is not limited to the content of the said embodiment, and unless it deviates from the scope of this invention, it is suitably with respect to the said embodiment. Can be changed.

1 Image forming system 3 LAN
4 External device 40 External control unit 100 First image forming device 102 Conveying path 110 Printer controller 124 Image forming unit 125 Communication unit 130 Document feeding unit 150 Main control unit 200 First reversing device 202 Conveying path 202a Inverting conveying path 300 Second Image forming apparatus 302 Transport path 324 Image forming section 325 Communication section 350 Main controller 360 Second reversing device 362 Transport path 362a Reverse transport path 400 Image reading apparatus 402 Transport path 410 Image reading section 500 Post-processing apparatus 502 Transport path

Claims (17)

An image forming system in which a plurality of image forming apparatuses each having an image forming unit for forming an image on a transfer medium are connected in series tandem,
The image forming unit performs processing of image data used for image formation, and includes a control unit that controls the image forming apparatus,
The control unit has a function of outputting an inspection image for obtaining calibration data of the image forming apparatus by the image forming apparatus and enabling acquisition of a reading result by the image reading unit,
The function prepares inspection image data to be output by one image forming apparatus, duplicates the data, and sends the original inspection image data and one of the copied inspection image data to each image forming apparatus. An image forming system that performs control to form an image on a different transfer medium in each image forming apparatus based on inspection image data received by each image forming apparatus. Each of the image forming apparatuses has an image forming control unit that controls the image forming unit,
2. The image according to claim 1, wherein the control unit includes a system control unit that processes image data used in each image forming apparatus and controls each image forming apparatus, and each image formation control unit. Forming system. Among the plurality of image forming apparatuses, in the image forming apparatus serving as the main machine, the image formation control unit provided in the image forming apparatus acquires the inspection image data, outputs the inspection image to a transfer medium, and duplicates the inspection image data. Then, the duplicated inspection image data is sent to the image forming apparatus as a sub machine,
In the image forming apparatus serving as the sub machine, the image forming control unit provided in the image forming apparatus performs transfer different from the transfer medium used for outputting the inspection image in the other image forming apparatus based on the copied inspection image data. 3. The image forming system according to claim 2, wherein an inspection image is output to a medium.   The control unit acquires and analyzes a reading result of the inspection image output from each image forming apparatus, and performs calibration processing of the image forming apparatus from which the inspection image is output based on the analysis result. The image forming system according to claim 1.   5. The control unit according to claim 1, wherein the control unit acquires and analyzes a reading result of the inspection image output from each image forming apparatus, and obtains calibration data of the image forming apparatus based on the analysis result. The image forming system according to claim 1.   The reading result is acquired by the image forming control unit of the image forming apparatus to which the inspection image giving the reading result is output, and the result is processed for image data used in each image forming apparatus and each image forming apparatus is processed. 6. The image forming system according to claim 5, wherein the system control unit generates calibration data based on the result.   The image forming system according to claim 6, wherein the image forming control unit of each of the image forming apparatuses performs analysis based on the reading result and sends the analysis result to the system control unit.   8. The image forming system according to claim 4, wherein calibration of each image forming apparatus is performed by an image forming control unit included in each image forming apparatus or by a system control unit. .   9. The control unit according to claim 4, wherein the control unit adjusts the calibration data with at least one image forming apparatus so that a calibration result of each image forming apparatus falls within a predetermined range. The image forming system described.   The image forming system according to claim 4, wherein the control unit stores respective calibration data used for calibration of each image forming apparatus.   The image forming system according to claim 4, wherein the control unit stores common calibration data used for calibration of each image forming apparatus.   When the inspection image is printed by the preceding image forming apparatus, the control unit sends the transfer medium on which the inspection image is formed by the preceding image forming apparatus to the succeeding image forming apparatus without reversing the front and back. The image forming system according to claim 1, wherein the sheet discharge control is performed without forming an image with the forming apparatus.   When printing the inspection image with the subsequent image forming apparatus, the control unit discharges the transfer medium supplied by the preceding image forming apparatus without forming the image with the preceding image forming apparatus, and outputs the subsequent image. Control is performed so that the image is sent to a forming apparatus, an inspection image is printed by one image forming apparatus on the subsequent stage, and the output face is positioned on the same side as the output face of the preceding image forming apparatus. The image forming system according to claim 1.   An image reading unit that reads an image of a transfer medium conveyed from an upper apparatus is provided at a position lower than the plurality of image forming apparatuses, and the image reading unit transmits a reading result to the control unit. The image forming system according to claim 1, wherein:   The image forming system according to claim 14, wherein the plurality of inspection images output by the plurality of image forming apparatuses are read by the same image reading unit. An image forming control method for controlling image formation in an image forming system in which a plurality of image forming apparatuses each having an image forming unit for forming an image on a transfer medium are connected in series tandem,
The image forming apparatus has a function of outputting an inspection image for obtaining calibration data of the image forming apparatus and enabling acquisition of a reading result by the image reading unit,
The function prepares inspection image data to be output by one image forming apparatus, duplicates the data, sends the original inspection image data and the replicated inspection image data to each image forming apparatus, and outputs each image. An image forming control method, wherein each image forming apparatus performs control to form an image on a different transfer medium based on inspection image data received by the forming apparatus. A program executed by a control unit that controls an image forming system in which a plurality of image forming apparatuses each having an image forming unit that forms an image on a transfer medium are connected in series tandem,
A step of outputting an inspection image for obtaining calibration data of the image forming apparatus by the image forming apparatus and enabling acquisition of a reading result by the image reading unit;
In the step, the inspection image data to be output by one image forming apparatus is prepared and the data is duplicated, and the original inspection image data and the copied inspection image data are sent to the respective image forming apparatuses, A program for forming an image on a different transfer medium in each image forming apparatus based on inspection image data received by the forming apparatus.

Images